Millions of syringes, such as that depicted in FIG. 1A (2), are consumed in healthcare environments every day. A typical syringe (2) comprises a tubular body (4), a plunger (6), and an injection needle (8). As shown in FIG. 1B, such a syringe (2) may be utilized not only to inject fluid into a patient, but also to withdraw or expel fluid out of or into a container such as a medicine bottle, vial, bag, or other drug containment system (10). Indeed, due to regulatory constraints in some countries such as the United States as well as sterility maintenance concerns, upon use of a medicine bottle (10) with a syringe (2) as shown in a particular patient's environment, such medicine bottle may only be utilized with a single patient and then must be disposed of—causing significant medical waste from bottle and remaining medicine disposal, and even contributing to periodic shortages of certain critical drugs. Referring to FIG. 2A, three Luer-type syringes (12) are depicted, each having a Luer fitting geometry (14) disposed distally, so that they may be coupled with other devices having similar mating geometry, such as the Luer manifold assembly (16) depicted in FIG. 2B. The Luer fittings (14) of the syringes of FIG. 2A may be termed the “male” Luer fittings, while those of FIG. 2B (18) may be termed the “female” Luer fittings; one of the Luer interfaces may be threaded (in which case the configuration may be referred to as a “Luer lock” configuration) so that the two sides may be coupled by relative rotation, which may be combined with compressive loading. In other words, in one Luer lock embodiment, rotation, possibly along with compression, may be utilized to engage threads within the male fitting which are configured to engage a flange on the female fitting and bring the devices together into a fluid-sealed coupling. In another embodiment, tapered interfacing geometries may be utilized to provide for a Luer engagement using compression without threads or rotation (such a configuration may be referred to as a “slip-on” or “conical” Luer configuration). While such Luer couplings are perceived to be relatively safe for operators, there is risk of medicine spilling/leaking and parts breakage during the loading to provide a Luer coupling. The use of needle injection configurations, on the other hand, carries with it the risk of a sharp needle contacting or poking a person or structure that is not desired. For this reason, so called “safety syringes” have been developed.
One embodiment of a safety syringe (20) is shown in FIG. 3, wherein a tubular shield member (22) is spring biased to cover the needle (8) when released from a locked position relative to the syringe body (4). Another embodiment of a safety syringe (24) is shown in FIGS. 4A-4B. With such a configuration, after full insertion of the plunger (6) relative to the syringe body (4), the retractable needle (26) is configured to retract (28, 26) back to a safe position within the tubular body (4), as shown in FIG. 4B. Such a configuration which is configured to collapse upon itself may be associated with blood spatter/aerosolization problems, the safe storage of pre-loaded energy which may possible malfunction and activate before desirable, loss of accuracy in giving full-dose injections due to residual dead space within the spring compression volume, and/or loss of retraction velocity control which may be associated with pain and patient anxiety.
Further complicating the syringe marketplace is an increasing demand for pre-filled syringe assemblies such as those depicted in FIGS. 5A and 5B, which generally comprise a syringe body, or “drug enclosure containment delivery system”, (34), a plunger tip, plug, or stopper (36), and a distal seal or cap (35) which may be fitted over a Luer type interface (FIG. 5A shows the cap 35 in place; FIG. 5B has the cap removed to illustrate the Luer interface 14). Liquid medicine may reside in the volume, or medicine reservoir, (40) between the distal seal and the distal end (37) of the plunger tip (36). The plunger tip (36) may comprise a standard butyl rubber material and may be coated, such as with a biocompatible lubricious coating, to facilitate preferred sealing and relative motion characteristics against the associated syringe body structure and material. The proximal end of the syringe body (34) in FIG. 5B comprises a conventional syringe flange (38), such as that known as a “Gerresheimer” flange configuration. The syringe body (34) preferably comprises a translucent material such as a glass or polymer. To form a contained volume within the medicine chamber or reservoir (40), and to assist with expulsion of the associated fluid through the needle, a plunger tip (36) may be positioned within the syringe body (34). The syringe body may define a substantially cylindrical shape (i.e., so that a plunger tip 36 having a circular cross sectional shape may establish a seal against the syringe body), or be configured to have other cross sectional shapes, such as an ellipse.
Such assemblies are desirable because they may be standardized and produced with precision in volume by the few manufacturers in the world who can afford to meet all of the continually changing regulations of the world for filling, packaging, and medicine/drug interfacing materials selection and component use. Such simple configurations, however, generally will not meet the new world standards for single-use, safety, auto-disabling, and anti-needle-stick. Thus certain suppliers have moved to more “vertical” solutions, such as that (41) featured in FIG. 5C, which attempts to meet all of the standards, or at least a portion thereof, with one solution; as a result of trying to meet these standards for many different scenarios, such products may have significant limitations (including some of those described above in reference to FIGS. 3-4B) and relatively high inventory and utilization expenses.
There is a need for improved injection systems which address the shortcomings of currently-available configurations. In particular, there is a need for safety injection solutions which may utilize the existing and relatively well-controlled supply chain of conventionally delivered pre-filled syringe assemblies such as those described in reference to FIGS. 5A and 5B.